F24 Week 4 Biology and Psychology PDF

Biology and Psychology PSYC-1113: Psychology for HSF Fall 2024 | Week 4  Agenda Welcome Reminder: Quiz 2 attempts due by Sunday Week 3 assignment and Quiz 1 debrief Quick review Neurons The Brain Assignment Review: Nature vs Nurture...

Biology and Psychology PSYC-1113: Psychology for HSF Fall 2024 | Week 4  Agenda Welcome Reminder: Quiz 2 attempts due by Sunday Week 3 assignment and Quiz 1 debrief Quick review Neurons The Brain Assignment Review: Nature vs Nurture Nature environmental Nurture the inborn, innate influences that shape character of an behaviours organism Images CC0 from Pixabay Review: Divisions of the Nervous System Copyright © 2023 Cengage Learning Canada, Inc. Neurons  Neurons and Glial Cells Neurons are specialized cells of the nervous system receive and transmit electrochemical signals to and from neighbouring neurons by “firing” Humans have more than 100 billion neurons at birth, mostly in the brain. The nervous system also contains glial cells. These cells have several functions including to: nourish and insulate neurons direct growth of neurons remove dead neurons and waste products from the nervous system Copyright © 2023 Cengage Learning Canada, Inc.  Sensory, Interneurons and Motor Neurons Sensory (afferent) neurons transmit messages from sensory receptors to the spinal cord and brain. Interneurons are neurons that connect sensory and motor neurons. Motor (efferent) neurons transmit messages from the brain or spinal cord to muscles and glands. Copyright © 2023 Cengage Learning Canada, Inc.  Parts of a Neuron Neurons vary according to their function and location. They are composed of – a cell body – dendrites – an axon – axon terminals, or terminal buttons Neurons carry messages from the dendrites or cell body through the axon to the terminals. Copyright © 2023 Cengage Learning Canada, Inc. Parts of a Neuron Copyright © 2023 Cengage Learning Canada, Inc.  Parts of a Neuron cont’d The cell body contains the nucleus, which uses oxygen and nutrients to generate the energy necessary for the neuron to do its work. Dendrites are root-like structures, attached to the cell body of a neuron, that receive impulses from other neurons. The axon is a long, thin part of a neuron that transmits impulses to other neurons from branching structures called terminals or terminal buttons. The terminal buttons transmit messages from the neuron to dendrites of neighbouring neurons. Copyright © 2023 Cengage Learning Canada, Inc.  Myelin Myelin is a fatty substance that encases and insulates some axons, facilitating the transmission of neural impulses. grey matter: unmyelinated neurons; some involved in spinal reflexes white matter: myelinated neurons that carry messages to and from the brain Copyright © 2023 Cengage Learning Canada, Inc.  Myelin cont’d Myelination is part of the maturation process. In the disease, multiple sclerosis, myelin is replaced with a hard, fibrous tissue that throws off the timing of neural impulses and disrupts muscular control. Copyright © 2023 Cengage Learning Canada, Inc. How Neurons Communicate The Synapse A synapse consists of an axon terminal button from the transmitting neuron a dendrite or the body of a receiving neuron a tiny fluid-filled space between the two that is called the synaptic cleft Copyright © 2023 Cengage Learning Canada, Inc. Watch  Neural Impulses Neural impulses are electrochemical messages that travel within neurons, up to 360 km/h. Copyright © 2023 Cengage Learning Canada, Inc.  Neural Impulses polarization: the difference in electrical charge that readies a neuron for firing; depolarization: chemical stimulation of resting neurons resting potential: a neuron’s electrical potential when it is not responding to other neurons action potential: the electrical potential when a neural impulse is being conducted along a neuron’s axon Copyright © 2023 Cengage Learning Canada, Inc. Neural Impulses Copyright © 2023 Cengage Learning Canada, Inc.  Neural Impulses Firing is the conduction of a neural impulse along the length of a neuron. Firing releases neurotransmitters. Firing works on the all-or-none principle: – The neural impulse is always of the same strength whenever action potential is triggered. The refractory period follows. During this recovery period, a neuron will not fire. Copyright © 2023 Cengage Learning Canada, Inc.  Neurotransmitters Neurotransmitters are chemical substances that are involved in the transmission of information from one neuron to another are released by synaptic vesicles, sacs in the axon terminals fit into receptor sites on dendrites of receiving neurons can be excitatory or inhibitory Reuptake is the reabsorption of the released neurotransmitter by the releasing neuron. Copyright © 2023 Cengage Learning Canada, Inc. The Synapse Copyright © 2023 Cengage Learning Canada, Inc. Summary  Neurotransmitters This material will be reviewed during lecture IF time permits  ACh Acetylcholine (ACh) is a neurotransmitter that controls muscle contractions and memory formation. ACh is prevalent in the hippocampus. –hippocampus: a part of the limbic system of the brain that is involved in memory formation Lack of ACh is associated with Alzheimer’s disease. Copyright © 2023 Cengage Learning Canada, Inc.  Dopamine Dopamine is a neurotransmitter involved in the perception of pleasure, voluntary movement, learning, and memory. Deficiencies of dopamine are linked to Parkinson’s disease; excesses are linked to schizophrenia. Copyright © 2023 Cengage Learning Canada, Inc.  Norepinephrine Norepinephrine is an excitatory neurotransmitter involved in arousal, learning, memory, and eating. Excesses are linked to mood disorders. Deficiencies of both ACh and norepinephrine particularly impair memory formation. Copyright © 2023 Cengage Learning Canada, Inc.  Serotonin Serotonin is a neurotransmitter involved in emotional arousal and sleep; deficiencies are linked to eating disorders, alcoholism, depression, aggression, and insomnia. Copyright © 2023 Cengage Learning Canada, Inc.  Glutamate Glutamate is an excitatory neurotransmitter that has an important role in memory and learning, and is found throughout a healthy nervous system. Copyright © 2023 Cengage Learning Canada, Inc.  GABA Gamma-aminobutyric acid (GABA) is an inhibitory neurotransmitter that calms anxious reactions. – Alcohol and tranquillizers bind with GABA receptors to inhibit anxiety. GABA deficiencies are linked to depression. Copyright © 2023 Cengage Learning Canada, Inc.  Endorphins Endorphins are inhibitory neurotransmitters that act as naturally occurring painkillers; they are structurally and functionally like morphine. – responsible for “runner’s high”: the feeling of well-being connected to a physically strenuous workout Copyright © 2023 Cengage Learning Canada, Inc.  Summary Consider creating a table to summarize this information on neurotransmitters. The Brain  Brain Plasticity plasticity: ability of the brain to adapt and change The brain remains “plastic” or changeable throughout the life span. Brain imaging of taxicab drivers has revealed increased growth in areas of the hippocampus associated with navigational mental mapping. Children who have lost the left hemisphere because of medical problems have speech functions transferred to the right hemisphere; the brain “reorganizes.” Copyright © 2023 Cengage Learning Canada, Inc. 2-34 The Brain Copyright © 2023 Cengage Learning Canada, Inc.  The Forebrain The forebrain is the forward-most part of the brain; its structures are the thalamus, hypothalamus, limbic system, and cerebrum (cerebral cortex and corpus callosum). Copyright © 2023 Cengage Learning Canada, Inc.  The Limbic System The limbic system is made up of structures that include the amygdala, the hippocampus, and parts of the hypothalamus. It is evolved fully only in mammals and forms a fringe along the inner edge of the cerebrum. The limbic system is involved in memory and emotion, and in the drives of hunger, sex, and aggression. The Limbic System The limbic system is made up of structures that include the amygdala, the hippocampus, and parts of the hypothalamus. It is evolved fully only in mammals and forms a fringe along the inner edge of the cerebrum. The limbic system is involved in memory and emotion, and in the drives of hunger, sex, and aggression. The amygdala is a part of the limbic system that apparently facilitates stereotypical aggressive responses. The amygdala is also connected with vigilance. It is involved in emotions, learning, and memory, and it behaves sort of like a spotlight, focusing attention on matters that are novel and important to know more about. The hippocampus is an important structure for learning and memory. Copyright © 2023 Cengage Learning Canada, Inc. The thalamus is a relay station for sensory information to the cortex and in the functions of sleep and attentiveness Hypothalamus: a bundle of nuclei below the thalamus that regulates motivation, emotion, body temperature, hunger, thirst, sexual behaviour, aggression, and caring for offspring  Cerebrum: the large mass of the forebrain, which consists of two hemispheres (right and left) – cerebral cortex: the wrinkled surface area (grey matter) of the cerebrum – corpus callosum: a thick fibre bundle that connects the hemispheres of the cortex Copyright © 2023 Cengage Learning Canada, Inc.  Cerebral Cortex The cerebral cortex is the outer coating of the cerebrum; the largest mass of the forebrain divided into two hemispheres (right and left), and four lobes: frontal, parietal, temporal, and occipital  Lobes of the Cerebral Cortex frontal lobe is the decision-making part of the brain responsible for planning, problem solving, executive functioning, and other thought processes controls voluntary muscle movements contains the motor cortex parietal lobe receives sensory messages from the body contains the somatosensory cortex temporal lobe processes auditory information, including language contains Broca’s and Wernicke’s areas: key language regions occipital lobe processes visual information The Forebrain- The Cerebral Cortex Copyright © 2023 Cengage Learning Canada, Inc.  The Somatosensory Cortex is located behind the central fissure at the top of the brain in the parietal lobe receives messages from skin senses all over the body – warmth and cold, touch, pain, movement One side of the brain is limited to the sensory and motor activity on one side of the body. Damage on one side of the brain impacts activity and sensation on the opposite side of the body. Copyright © 2023 Cengage Learning Canada, Inc.  The Motor Cortex lies in the frontal lobe at the top of the brain is across the valley of the central fissure from the somatosensory cortex Neural impulses in the motor cortex are linked to muscular responses throughout the body. –The right side of the brain controls the left side of the body and vice versa, so injury to one side affects movements on the opposite side. 2-46 Copyright © 2023 Cengage Learning Canada, Inc.  Left Brain, Right Brain? The left and right hemispheres have different functional responsibilities, with some overlap. The left hemisphere controls the right side of the body. relatively more involved in logical analysis, language, and mathematical computation The right hemisphere controls the left side of the body. usually superior in visual–spatial functions, facial recognition, and emotional understanding 2-47 Copyright © 2023 Cengage Learning Canada, Inc.  The Corpus Callosum corpus callosum: a thick fibre bundle that connects the hemispheres of the cortex  The Corpus Callosum Epilepsy involves temporary disturbances of brain functions from sudden neural discharges. Severe cases of epilepsy may require split-brain operations, severing the corpus callosum. It is usually successful in controlling seizures; most patients do not suffer severe functional losses. Certain tasks can bring out strange behaviour, such as each hemisphere having a “mind of its own”: the inability of one hemisphere to communicate with the other. Copyright © 2023 Cengage Learning Canada, Inc.  The Hindbrain The hindbrain is made up of structures that include the medulla, the pons, and the cerebellum and is located at the point where the spinal cord rises to meet the brain. The Hindbrain medulla: regulates basic functions such as heart rate, blood pressure, and respiration pons: transmits information related to movement, sleep, alertness, and respiration cerebellum: regulates balance and muscle coordination; controls other automatic functions Reticular formation: connects to the midbrain and forebrain; regulates arousal, attentiveness, and sleep Copyright © 2023 Cengage Learning Canada, Inc.  Reticular formation Image source: https://www.google.com/url?sa=i&url=https%3A%2F%2Ftwitter.com%2Freticularf&psig=AOvVaw3r7NccSJ5v4nPUyVUgxxbm&ust=166385798 9150000&source=images&cd=vfe&ved=0CAwQjRxqFwoTCLDokLSQpvoCFQAAAAAdAAAAABAM  The Cortex and Language Two key language areas lie within the (usually left) cortex that contains language functions. Damage to either area is likely to cause aphasia—the inability to understand or produce language. Wernicke’s aphasia: difficulty comprehending the meaning of spoken language Broca’s aphasia: difficulty producing speech. Copyright © 2023 Cengage Learning Canada, Inc. Broca’s and Wernicke’s Areas 2-56 Copyright © 2023 Cengage Learning Canada, Inc.  Assignment – Muddiest Point In a written paragraph, please identify one concept from this week’s lesson that challenged you. What questions do you still have about this concept? What strategies can you use to learn this information? This assignment is worth 3% of your final grade.